1. Field of the Invention
The present invention relates to a product which is useful in the fabrication of semiconductor chips
2. Description of Related Developments
Currently, silicon wafers with multiple printed circuitry are diced (or sawed) into individual circuits (chips) by first placing the wafer onto a dicing film (a polymeric support film having a tacky surface which holds the wafer in place during the dicing operation. The wafer is then partially cut through its thickness by a dicing implement (e.g., a diamond-impregnated wheel). The wafer is then cracked into individual chips during a cracking procedure, and the chips are separated by stretching the support film. The chips are then picked up individually by a vacuum chuck to be placed into an appropriate chip carrier. A drop of conductive adhesive is placed onto the chip carrier where the chip is to be placed. The adhesive is then cured to secure the chip into place and provide a ground for the chip during the step in which wires are bonded to the chip.
It has also been suggested that both cost reduction and yield improvement can be achieved in the actual fabrication of the semiconductor products by elimination of the application of conductive adhesive to the chip carrier. This could be accomplished by applying conductive adhesive to the dicing film itself so that the adhesive and chip are attached to one another prior to the dicing step. During dicing the adhesive would hold the wafer on the support film. The dicing implement would cut through the entire thickness of the wafer, through the adhesive and only partially into the carrier film itself in order to still provide the needed support for the wafer. After dicing, the chips would be picked from the carrier film along with the conductive adhesive and would be placed onto the chip carrier. The adhesive would then be cured at the appropriate temperatures to develop the chip/carrier bond and the desired conductivity.
Although such a conductive adhesive/dicing film combination represents a theoretical improvement over the use of a dicing film having a mere surface tackiness, problems have been encountered in cleanly removing the wafer/adhesive combination from the support film after the wafer and adhesive have been brought into contact with one another.